Process and apparatus for producing a dry-pressed moulding from a particulate or granular moulding material
US4788023A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 5, 1986 |
| Grant date | Nov 29, 1988 |
| Priority date | — |
| Expiry date | Dec 5, 2006 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB30B15/302
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process and apparatus for producing a dry-pressed molding from a particulate or granular molding material such as a ceramic molding composition in which the composition is initially drawn into a loading cavity by applying a vacuum thereto. The loading cavity is formed by a first mold half and a shooting head having a molding surface the shape of which determines the shape of a premolding which is formed upon entry of the composition into the loading cavity and sufficiently compressed to retain its shape after the shooting head has been removed to allow a second mold half to be positioned over the first mold half. The shape of the part of the premolding formed by the shooting head molding surface differs from that of the second mold half in such a way that, on final pressing, the compression starts in the areas of relatively greater thickness of the premolding before it starts in the areas of relatively smaller thickness so that the compression ratio is maintained approximately constant over the whole of the area of the molding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.